Nerve growth factor (NGF) is a hormone that is necessary for the growth and development of the sensory and sympathetic neurons. The mechanism by which this occurs is now beginning to be uncovered. The purpose of the project is to look at the binding, sequestration and internalization of NGF with respect to both sensory and sympathetic neurons. To investigate further the affect of calcium ions on the biological activity of NGF. It has been shown that calcium ions are needed in the assay medium of sensory neurons for them to grow neurites in the presence of NGF. Finally, to determine the extent to which NGF interacts with other proteins, especially acidic proteins. It has been shown that NGF interacts with serum albumin and many other acidic proteins We want to determine how specific these interactions are and what affects the interactionshave on the biological activity of NGF.